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Role of phenology in differentiation of plant niches: quantitative and comparative approach using a large set of species
Huang, Lin ; Herben, Tomáš (advisor) ; van Kleunen, Mark (referee) ; Dostál, Petr (referee)
Niche differentiation is the most recognized species coexistence mechanism, of which, the temporal differentiation of species, i.e. phenological differentiation has gained an increasing interest of ecologists. However, as an important dimension of phenology, the phenology of growth has drawn relatively few attentions due to the lack of sufficient phenological data. Therefore, the aim of this thesis is to examine potential role of temporal differentiation of plant growth patterns in plant coexistence. I first collected data on growth phenology of 381 perennial herbs in the Botanical Garden of Charles University in Prague within one growing season (in 2015). Using this database, I addressed the general patterns of growth phenology among perennial herbs. I distinguished two contrasting growth patterns: (1) species with early peak growth had high standardized growth rates in contrast to late species, reflecting the survival under forest canopy, where species are selected to grow early and fast before the development of tree canopy which restricts their size; (2) tall species showed later peak growth than short species, associating with (asymmetric) competition for light in open habitats, where the main selection factor is for tall stature, which cannot be attained early in the season. Then, by linking...
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Study of plant dispersal in river corridors using molecular marker
Fér, Tomáš ; Herben, Tomáš (advisor) ; Chrtek, Jindřich (referee) ; Tribsch, Andreas (referee)
5 Summary The thesis presents how the use of molecular markers (AFLPs and microsatellites) can help when studying plant dispersal in river systems. Analysis and interpretation of the spatial pattern of genetic variation allowed to address and discuss following aspects of long-distance dispersal in these linearly structured systems: (1) the extent of long-distance dispersal, (2) the intensity of vegetative long-distance dispersal, (3) unidirectional transport along the streams, and (4) dispersal among rivers. The first part of the PhD. thesis presents several general aspects of plant dispersal, methodological approaches used to detect dispersal, and possibilities of analysis and interpretation of the molecular data. It also gives a short introduction to the methodology used in the particular studies, summarizes the results of all studies, and discusses how differences detected by molecular markers correspond to dispersal possibility (e.g., by water, by wind) of the selected species. The second part contains a set of four papers, each focusing on a detailed survey of dispersal possibilities of one of four plant species within the river system of the Cidlina, the Mrlina and partly also the Labe Rivers (Czech Republic). Above- mentioned aspects of dispersal in river systems are further discussed in the light...
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Plant body as a behavioural platform - an ecologist's insight
Weiser, Martin ; Herben, Tomáš (advisor) ; Šmilauer, Petr (referee) ; Novoplansky, Ariel (referee)
Conceptualisation of plant behaviour, or plant phenotypic plasticity, has been proven to be useful both on the ecosystem scale and on the level of individuals, as it allows to predict differentiation of species across ecosystems or results of interactions among individuals. Between these extremes is a vast array of processes that drive community assembly. These processes are difficult to predict, be it at the individual level or based on whether a whole species is plastic or non-plastic. These processes are traditionally investigated at the species level. In this thesis, however, I instead show how species-specific life histories delineate plant behaviour. I hope to convince the reader that it is the plant body, or at least its species-specific properties, not merely its non-specific, theoretical degree of plasticity, that should be used to explain actual cases where plant behaviour underpins species coexistence. As evidence for my case, I present four studies, each of them dealing with different part of the plant body that underlies different aspects of plant behaviour. In the first study, I show how species' life- history traits are coordinated with their responses to neighbour presence and resource shortage, both of these delivered in the form of changing light quantity and quality. Not only the...
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Community ecology from the perspective of classic and bayesian statistics
Klimeš, Adam ; Keil, Petr (advisor) ; Herben, Tomáš (referee)
Community ecology from the perspective of classic and Bayesian statistics Ekologie společenstev z hlediska klasické a Bayesovské statistiky Řešitel: Adam Klimeš Vedoucí práce: Mgr. Petr Keil, Ph.D. Abstract Quantitative evaluation of evidence through statistics is a central part of present-day science. Bayesian approach represents an emerging but rapidly developing enrichment of statistical analysis. The approach differs in its foundations from the classic methods. These differences, such as the different interpretation of probability, are often seen as obstacles for acceptance of Bayesian approach. In this thesis I outline ways to deal with the assumptions of Bayesian approach, and I address the main objections against it. I present Bayesian approach as a new way to handle data to answer scientific questions. I do this from a standpoint of community ecology: I illustrate the novelty that Bayesian approach brings to data analysis of typical community ecology data, specifically, the analysis of multivariate datasets. I focus on principal component analysis, one of the typical and frequently used analytical techniques. I execute Bayesian analyses that are analogical to the classic principal components analysis, I report the advantages of the Bayesian version, such as the possibility of working with...
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The role of biotic interactions in population biology of meadow plants
Janovský, Zdeněk ; Herben, Tomáš (advisor) ; Lepš, Jan (referee) ; Ehrlen, Johan (referee)
In present thesis, I treat the topic of impacts of plant-animal interactions, namely herbivory and pollination, on plant life cycle and lifetime fitness. First, I identify the components of the impact of plant-animal interactions: i) interaction frequency; ii) per-interaction effect; iii) sensitivity of the plant's life cycle to the changes in vital rate impacted by the animals. Furthermore, I also classify other causes changing the outcome of a plant-animal interaction into two categories: i) plant's traits; ii) plant's environment. A review of extant literature on the topic revealed that especially the role of plant's environment in changing the outcome of plant-animal interactions is largely understudied and I attempt to reduce this gap in knowledge in the five detailed studies encompassed in this thesis. The detailed studies focus on a model system of Central European wet grasslands and especially on three species typical to it: Succisa pratensis, Achillea millefolium and A. ptarmica. The first two studies examine the effects of environment on frequency of plant- animal interactions. The next two studies are more integrative, one focusing on the impacts of different herbivore groups on the complete life cycle and the other on interaction of herbivory and pollination on plant lifetime fitness....
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Dynamical pollination models
Smyčka, Jan ; Herben, Tomáš (advisor) ; Těšitel, Jakub (referee)
Dynamical pollination models (abstract) Pollination is a complex biological phenomenon which may include many interacting plant and animal species. In such a case, and especially when we are interested in effects of spatial structure, it can be helpful to use some formal approach of study, as is dynamical modelling. This thesis describes common methods for pollination modelling in space. The pollination can be divided into two consequent processes - pollinator movement and pollen carryover. Simple method of pollination movement modelling is using some random particle movement patterns, e.g. Brownian motion. This approach is useful mostly for systems with one plant species, or at large scales. More accurate, but difficult, posibility is modelling pollinators" movement through some decision making process based on their behaviour. Pollen carryover models are the necessary "translation" of pollinator movement to variables important for plants. A part of this work is also an analysis of certain pollination models. Their assumptions, predictions and modifications for not yet tackled problems are discussed.
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Horses and vegetation
Třeštíková, Tereza ; Herben, Tomáš (advisor) ; Mládek, Jan (referee)
Many studies show that large herbivores can have an important impact on the composition of vegetation. With the establishment of a year round, low density grazing regime, plant ecologists and nature managers expect that through selective grazing, herbivores will create a mosaic of different vegetation communities varying in structure and plant species composition. It is believed that such a mosaic in the end will guarantee a high degree of biodiversity. Grazing will, therefore, seem to be a suitable means to maintain grass. Also important is the ability of herbivores affect vegetation through endozoochory. In this thesis I have tried to find out what species of diet horses prefer regarding to plant species and what plant species they can spread through out endozoochory. I have compared this knowledge with the composition of pasture and meadow vegetation at the researched locality in Malenice and Hoslovice. With the purpose of finding out the preferences I established spots where I registered data on vegetation before pasture and the time intervals during the pasture. Afterwards, I researched the amount of sprouts and the composition of seedlings in excrements that I let germinate. I had to create phytocenologic shots from the pastures and meadows to compare the species of composition of grazed and...
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Populační biologie rostlin napadených systémovými parazity
Koubek, Tomáš ; Herben, Tomáš (advisor) ; Šmilauer, Petr (referee) ; Wennström, Anders (referee)
Three separate studies of the effect of plant pathogen on population biology of its host are presented in the thesis. Two are using field data about a widespread system of plant Falcaria vulgaris and its systemic rust fungus Puccinia sii-falcariae. The first study shows, that the disease prevalences in 40 populations of the plant were correlated with the moisture, the soil reaction and the cover of the herb layer at the localities. This was probably a result of the interaction of the life history of the plant and different effect the disease has at various localities. Similar pattern was found in the second study that aimed to determine long-term effect of the disease at the population level at four chosen localities over 4-5 years. Population growth rates were only rarely predicted to be higher for the healthy part of the population when compared with the whole population. Other analyses have however found big differences among years and localities. The locality type (slope vs. field populations) was important factor influencing population stage composition and importance of life cycle transitions for the growth of the population. Finally, the last study explores the possibility that systemic infection in clonal plants might be able to select against clonality. The result of the modelling showed that more...
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Phenotypic plasticity and its role in plant invasions
Hlavička, Matěj ; Herben, Tomáš (advisor) ; Skálová, Hana (referee)
Phenotypic plasticity is the ability of given genotype to produce different phenotypes as a response to environmental cues. Its capability of adaptive response draws an attention of invasion biologists. Although many studies have been performed, the true role of plasticity in an invasion process is still unclear. Comparative experiments suffer from several major constraints - insufficiency in revealing adaptive value of plastic response and uncertain linkage between plasticity and trait value. Further experiments could be focused to reaction norms of fitness instead of trait plasticity. Also, the interspecific interaction of plastic responses is definitely an underestimated mechanism and deserves far more attention than it does today. Possible implications of plant phenotypic plasticity in predicting future invasions require further reaserch.
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